US GLOBEC Fundamental Discoveries and Surprises David Mountain

How to Choose? Fundamental discoveries or findings - integrative, bigger picture Surprises - big, small … whatever… Apologies

Northwest Atlantic Salinity anomaly Low salinity in 1990s – particularly during GLOBEC

Phytoplankton – seasonal timing/abundance Zooplankton – community structure Cod & Haddock early life survival consistent with stock abundance Northwest Atlantic Salinity anomaly Gulf of Maine Georges Bank

So where did the low salinity come from? In flow from Scotian Shelf Gulf of St. Law & northArctic outflow

So where did the low salinity come from? In flow from Scotian Shelf Gulf of St. Law & northArctic outflow Ecosystem changes are driven by external advection And the response of the internal system dynamics to that forcing

Multi-decade simulation captures system variability Response to large-scale atmospheric forcing changing the amount and source of upwelling High NPGO – upwelling from deeper depths (higher nutrients, lower O 2 ) (Di Lorenzo et al., 2008)

Zooplankton: Community changes caused by horizontal advection associated with that same forcing (PDO variability) (Keister et al., 2011)

Zooplankton: Community changes caused by horizontal advection associated with that same forcing (PDO variability) Ecosystem changes are driven by external advection (vertical and horizontal) And the response of the internal system dynamics to that forcing (Keister et al., 2011)

Coastal Gulf of Alaska Cross-shelf gradients in factors controlling production Macro- vs micro- nutrients Large vs small phytoplankton Large vs small micro-zoo Large vs small copepods Different dynamics over short distances Single quantitative framework (…model…) needs all of the above to represent both regions simultaneously HNLC LNHC (Hinckley et al., 2009)

Coastal Gulf of Alaska Cross-shelf gradients in factors controlling production Macro- vs micro- nutrients, Large vs small phytoplankton, Large vs small micro-zoo Large vs small copepods Different dynamics over short distances Single quantitative framework (…model…) to represent both regions simultaneously needs all of the above HNLC LNHC Changing climate likely will influence these regions differently with different implications for the local populations

Southern Ocean Onset of winter ice coverage Late Early Cold temperatures in 2002 Low winter krill survival in low ice algae concentrations Winter krill concentration (Lawson et al., 2008)

Biological ‘Hot Spots’ Regions where predators concentrate bathymetric, physical and biological conditions combine to provide consistent source of prey Influx of Circumpolar Deep Water - heat, nutrients higher PP - ties to the ACC Southern Ocean (Pinones et al., 2011)

Southern Ocean Ecosystem sensitive to climate change affecting both local atmospheric forcing and external advection associated with the ACC Biological ‘Hot Spots’ Regions where predators concentrate bathymetric, physical and biological conditions combine to provide consistent source of prey Influx of Circumpolar Deep Water - heat, nutrients higher PP - ties to the ACC

Surprises 3 flavors: - Unexpected - Assumed but didn’t find - Assumed and found

Unexpected Northwest Atlantic In 1990s Haddock early survival increased by x4 Cod early survival decreased by x4 And stock abundance changed similarly Fishery management to get some credit, but significant ecosystem component controlling change in stock abundance

Unexpected California Current System Low dissolved oxygen Oregon shelf (2002 obs) CALCOFI region (retrospective) Temporal trend of lower oxygen - adverse biological effects Upwelling of deeper, offshore waters (lower O 2 and higher nutrients) associated with higher NPGO/lower PDO Shoaling of hypoxic boundary (Bograd et al., 2008)

Unexpected California Current System Delayed upwelling in 2005 – Poor survival/condition for salmon and other organisms (major economic consequences)

Unexpected California Current System Delayed upwelling in 2005 – Poor survival/condition for salmon and other organisms (major economic consequences) Timing Matters

Expected but didn’t find: Northeast Pacific Expected inverse salmon production in CGOA and CCS – split of west wind drift Not found – other factors dominant in that variability

Assumed and found Species Matter Species specific characteristics (e.g., behavior, nutrition) necessary to explain observations

Assumed and found Species Matter Species specific characteristics (e.g., behavior, nutrition) necessary to explain observations Its not just total carbon (or other currency) Species Matter

Identified major pathways through which climate change will influence these ecosystems and the internal phy/bio dynamics controlling the system response to that forcing Summary:

GLOBEC! Summary Identified major pathways through which climate change will influence these ecosystems and the internal phy/bio dynamics controlling the system response to that forcing

But history and experience caution humility These are large, complicated ecosystems We have learned a lot

But history and experience caution humility These are large, complicated ecosystems We have learned a lot … so the new generation of researchers need have no fear of running out of new, fundamental discoveries to be made.

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